Unlike hunger, health, etc. that are at the base, Maslow's hierarchy says nothing about fulfilling your AI needs. Even if you argue this is a manifestation of "self", it's at the top, and least impactful for the broadest audience.
In a more enlightened society, one not prone to misusing information to persecute one another, he'd arguably be right.
It's likely much simpler: Larry thinks the solution to (his) immortality - or longevity at the very least - may be contained in Americans' collective DNA, and AI may be able to tease the answers out.
Mapping DNA is just another part of that schema.